Apparatus for developing sensitized layers by ammonia or other gas



S. H. MORSE Nov. 9, 1943.

APPARATUS FOR DEVELOPING SENSITIZED LAYERS BY AMMONIA OR OTHER GAS s Sheets-Sheet 1 Filed April 1 1941 S H. MORSE Nov 9, 1943.,

APPARATUS FOR DEVELOPING SENSITIZED LAYERS BY AMMONIA OR OTHER GAS Filed April 1 1941 3 Sheets-Sheet 2 S. H. MORSE APPARATUS FOR DEVELOPING SENSITIZED LAYERS BY AMMONIA OR OTHER GAS Filed April 1, 1941, a Sheets-Sheet s 62% W TTOEA EKS Patented Nov. 9, 1943 APPARATUS FOR DEVELOPING SENSITIZED LAYERS BY AMMONIA OR OTHER GAS Sydney Harold Morse, London, England, asslgnor to Wood, Mallabar & Company Limited, Lon-.

don, England, a British company Application April 1, 1941, Serial No. 386,364 In Great Britain April 13, 1940 Claims.

The invention relates to apparatus for developing photographic sensitized layers, in which the said layers are subjected to the action of ammonia. or other developing gas produced by heating the developing liquid inside the developing tank by means of an electric heater or heaters.

In apparatus of this kind it is essential that whilst the developing medium must be maintained at the right degree of humidity in order to obtain perfect development, at the same time moisture must not be allowed to condense upon the surface of the sensitized layer as this results in imperfect development.

The object of the invention is to provide a simple and compact apparatus for developing photographic sensitized layers by the action of ammonia or other gas which is in a continuous humid state in which the moisture content of the developing gas is prevented from condensing upon or in the immediate vicinity of the layers whilst they are passing through the apparatus.

The invention consists in an apparatus for developing photographic sensitized layers by ammonia gas or other vapour produced by heating the developing liquid inside the developing tank by means of an electric heater or heaters, and in which condensation is prevented in the whole of the developing area. The heater is arranged to go round each side of the developing tank, across the top, and underneath the plate which contains the liquid, and is of rectangular shape, whereby condensation will be prevented in the whole of the developing area. An important feature of the invention is the provision of means whereby an even and uniform circulation of the gases and vapours is produced.

The invention also consists in the further features hereinafter claimed.

Figure 1 is a cross section end view.

Figure 2 is an end elevation.

Figure 3 is a front elevation.

In carrying the invention into eiiect, a tank is I provided of D-shape cross section A which is perforated on the curve B for the exit of the ammonia gas orv other vapour which develops the layers. This tank A is supported by end frames C which are held together by stretcher bars D, and enclosed by cover plates E, which house the apparatus.

A feed plate F and coiling plate G are used for entry of the layers.

Mounted within the side frames are two main rollers H which are embraced by the endless blanket H and are rotated by gear I. At the back of the tank there is a longitudinal gap J which is used for ventilating purposes by a suction tube J and where the layers emerge from point K surplus gas will be drawn through tube J and taken out through the suction fan L into the open air outside the room or building.

Suitable gear is mounted on top of the apparatus as shown in Figures 1, 2 and 3, and a motor M is usIed to drive the gear I as well as the suction At the sideof the apparatus there is a supply tank N which contains the liquid which is allowed to feed into the D-shape tank A by a control'valve O, and this liquid drops into the bottom of the inside baffle plate P at Q.

In the cross section Figure 1, the heater R is shown which comes in the tank A at one end, and is underneath the baiile plate P and continues towards the opposite end, and is bent round and upwards near the perforated curve and returns across the top and down the side again and comes out at the entry for electrical connection which produces a heater of rectangular shape.

The baffle plate P shown in Figure 1 cross section is continued through the whole length of the tank A, and it is turned up at Point P to accommodate the liquid shown at P and at the top it is turned over at P for directing circulation of the gases. There is a lower additional baiiie plate P which has a gap allowing circulation as shown by the arrow.

The tank A has both ends sealed with cover plates A and these are fitted after assembling the heater and plates inside of the tank.

Atthermostat S may be fitted to control the hea The apparatus is employed in the following manner.

When-the motor M is started the heater R is also switched on, the rollers H are rotated and the endless blanket H is set in motion and the layers which are fed over feed plate F are drawn downwards and across the perforated plate B and aredeveloped by the ammonia or other gas and delivered at point K. The drop valve 0 is opened and the liquid runs in through a pipe at Q and is evaporated a P by the heater R which is underneath baffle plate P. The additional baffle plate P partly shuts in the heat given oil! by the lower part of heater R, and is used for a dua1 purpose; evaporation of the liquid is produced at P and circulation of the gases by utilizing the heat from P which goes forward up the slope of the base of baille plate P to the boxed in section T, and over the top at take place.

the coolest part of the tank by reason of the air currents in section J and condensation will take place there, and away from the whole area of perforated plate B.

Condensed liquid is allowed to run outthrough pipe V, and will drain away from the bottom of tank A, as shown in the drawings.

I declare that what I'claim is:

1. Apparatus for developing photographic sensitized layers by moist ammonia or other vapour comprising a D shaped developing chamber having a perforated curved surface, an inner baille plate fitted adjacent to and spaced from said surface, a single electric heater of rectangular form disposed between said ban'ie plate and said curved surface and adapted to conform in ourvature to said surface and an endless band adapted to move said layers over said surface.

2. Apparatus for developing photographic sensitized layers by moist ammonia or other vapour comprising, an outer casing, a D-shaped developer casing disposed inspaced relation within said outer casing and presenting upper and lower generally horizontal leg walls and a generally vertical standard wall and a generally vertically disposed convexly curved and perforated layer supporting and developer surface, a travelling belt for holding layers against and conveying them downwardly over said curved surface, an inner baflie plate disposed in generally parallel spaced related to said curved surface and having an extension lying above and generally parallel to the lower leg wall of the D-shaped casing and extending upwardly opposite the standard P where the gap widens and circulation will The back of the tank U will be wall of the D-shaped casing to form an ammonia retaining trough, heating means in the spaces between the inner baiiieand its extension and the curved surface and the lower leg wall of the D-shaped casing for vaporizing the trough contained ammonia and causing vapour thereof to rise by convection current in contact with the curved surface, and means for inducing an air current over said lower leg wall and said standard wall to cause them to be much cooler than the curved surface so that condensation will take place on said leg and standard walls and not on said curved surface.

3. An apparatus as defined in claim 2, in which the lower leg wall of the D-shaped casing slopes downwardly toward the standard wall to form a condensation collection trough, and in which there is included means for drawing oil condensation from said collection trough.

4. An apparatus as defined in claim 2 in which said heating means is generally rectangular in shape and includes a leg portion at each end of the D-sha'ped casing above the lower leg wall thereof, an end leg extending upwardly in curved generally parallel relation with the curved surface at each end of the D-shaped casing, and a horizontal leg connecting the upper ends of the end legs and generally paralleling the curved surface.

5. An apparatus as defined in'clairn 2 in which there is included an additional baiile wall partially enclosing the space between the generally horizontal extension of the inner baiiie and the lower leg wall of then-shaped casing.

SYDNEY HAROLD MORSE. 

